Furnace



' Jan. 23, 1968 J. H. JORDAN 3,364,905

FURNACE Filed March 28, 1966 5 Sheets-Sheet 1 JOHN H. JORDAN INVENTOR.

J. H. JORDAN Jan. 23, 1968 FURNACE 5 SheetsSheet 2 Filed March 28, 1966 JOHN H. JORDAN INVENTOR.

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FIG. 9

B wwwft Jan. 23, 1968 J. H. JORDAN 5 FURNACE Filed March 28, 1966 5 Sheets-Sheet 4 FIG. 5

JOHN H. JORDAN INVENTOR.

Jan. 23, 1968 J. H. JORDAN 3,364,905

FURNACE Filed March 28, 1966 5 Sheets-Sheet 5 JOHN H. JORDAN INVENTOR jzwmfi United States Patent 3,364,905 FURNACE John H. Jordan, Worcester, Mass., assignor to Riley Stoker Corporation, Worcester, Mass., a corporation of Massachusetts Filed Mar. 28, 1966, Ser. No. 537,766 7 Claims. (Cl. 122--494) ABSTRACT OF THE DISCLOSURE A supporting framework for supporting a burner box construction on a furnace wall, wherein the framework is supported for differential expansion and contraction, the sheet metal walls of the burner box being corrugated so that they can compensate for changes in size in the supporting framework.

In the design of steam generating units, it is common practice to group all of the fuel burners on one wall and to provide the air for all of the burners from a single wind box which envelopes the burners. Substantial problems are presented as steam generating units become larger and larger and the number of burners is increased and, therefore, the size of the wind box becomes larger. Most of the problems are presented by the fact that the boiler and furnace elements may expand at different rates with a change in temperature of the gases in the unit and the wind box. These problems of expansion and contraction are particularly accentuated Where the furnace is used with the effluent of a gas turbine system, wherein the air reaching theb urner box is at a considerable higher temperature than the normal forced draft air. These and other problems experienced with the prior art devices have been obviated in a novel manner by the present invention.

It is an outstanding object of the invention to provide a furnace having a Wind box associated with one wall wherein compensation is made for differential expansion and contraction between the wall and the wind box.

Another object of this invention is the provision of a furnace having means for supporting a wind box on one wall wherein the structure framework of the wind box is supported for differential expansion and contraction and the sheet metal elements associated with the structural support of the wind box are also capable of compensating for changes in size in the framework.

A further object of the present invention is the provision of a furnace having a sheet metal wind box in which means is provided in the wind box for permitting movement of one part relative to another.

It is another object of the instant invention to provide a furnace particularly adapted for use in a gas turbine cycle wherein expansion and contraction problems are not encountered when one shifts from using straight forced draft fan air to the efliuent of the gas turbine.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.

The character of the invention, however, may be best understood by reference to one of its structural forms, as illustrated by the accompanying drawings in which:

FIG. 1 is a vertical sectional view of a furnace embodying the principles of the present invention,

FIG. 2 is a perspective view of a portion of the furnace with portions broken away for clarity of illustration,

FIG. 3 is a horizontal sectional view of the invention taken on the line IIIIII of FIG. 2,

FIG. 4 is a vertical sectional view of the invention taken on the line IV-IV of FIG. 3,

fore the corner is reached are 3,354, Patented Jan. 23, 1958 FIG. 5 is a vertical sectional view of a portion of the invention taken on the line VV of FIG. 3,

FIG. 6 is a horizontal view of a portion of the invention as viewed along the line VIVI of FIG. 8,

FIG. 7 is a sectional view of a portion of the invention taken on the line VIIVII of FIG. 2,

FIG. 8 is a vertical sectional view of a portion of the invention taken on the line VIII-VIII of FIG. 2, and

FIG. 9 is a schematic diagram illustrating certain relationships in the structure of the invention.

Referring first to FIG. 1, wherein are best shown the general features of the invention, the furnace, indicated generally by the reference numeral 10, is shown as associated with a boiler 11 having a steam-and-water drum 12 and having water-wall tubes 13 lining the walls of a combustion chamber 14. The furnace has a front wall 15 on which are mounted a plurality of burners 16. In the preferred embodiment, the burners are arranged in three rows of four burners each to give a total of 12 burners. Mounted exteriorly of the combustion chamber 14 on the wall 15 and enveloping the burners 16 is a wind box 17. The lower end of the wind box is connected by a duct 18 through the exit of a gas turbine (not shown). The duct 18 carries a damper 19 for controlling flow of gas therethrough. The lower end of the wind box 17 is also connected by a duct 21 to a forced draft fan 22, the duct 21 containing a damper 23 for controlling the flow of air therethrough.

Referring now to FIG. 2, the burner box is provided with a structural supporting framework 24 and with a sheet metal sheathing 25. The framework is provided with inner horizontal beams 26 and outer horizontal beams 27. Associated with these horizontal beams are inner vertical beams 28 and outer vertical beams 29. Extending between the grid formed by the outer vertical beams 29 and the outer horizontal beams 27, on the one hand, and the inner horizontal beams 26 and the inner vertical beams 28, on the other hand, are horizontal connection beams 31 and diagonal beams 32. These horizontal and vertical beams make up a box-like framework having substantial strength and ability to carry the weight of the walls of the wind box. The wind box 17 is also provided with sheathing 25 consisting of a front wall 33, a left-hand side wall 34, a right-hand side wall 35, and a top wall 36. Extending upwardly from the top wall 36 of the wind box are supports 37 which are connected into the main framework of the boiler.

In FIG. 3 it can be seen that the front Wall 15 of the furnace is provided with spaced parallel water-wall tubes 13. This View shows the corner of the boiler and shows the manner in which the outermost pair of tubes 13 bejoined by a vertical plate 38 to which the left-hand side wall 34 is welded. The side wall is provided with a first section 39 which is provided with horizontal corrugations adjacent the front wall 33 I and with an outer section 41 which is provided with large respectively, above and below the plate 44. Extending between the plates 46 and '52 and passing through the slot 45 is a pin 47 of square cross-section.

FIG. 4 shows the details of construction at a lower corner of the combustion chamber where the water-wall tubes 13 are bent from a vertical position to an inclined 3 position to form a hopper. In this view, it can be seen that the wind box 17 is provided with a rear wall 48 of short vertical extent consisting of sheet metal bent to provide vertical corrugations. This rear wall is welded at its upper end to a horizontal plate 49 extending horizontally outwardly from the row of tubes 13.

FIG. shows greater detail of the means for connecting the wall to the framework of the wind box, particularly at the corner, shown in FIG. 3. The plate 44, which is attached to the front wall of the furnace, also extends outwardly to the extreme corner of the boiler and is welded to a buckstay beam 51 which extends along the adjacent side wall of the furnace. As is evident in this view, not only is the plate 46 provided extending forwardly from the front wall of the furnace, but also the lower plate 52, the pin 47 extending between the two plates and being locked in them. As is evident in FIG. 3 and FIG. 5, the pin 47 is square shaped and resides in the elongated slot 45 in the plate 44, which arrangement permits relative transverse movement between the plates but not longitudinal movement. In this view can be seen the way in which the forward edge of the horizontallycorrugated section 39 of the side wall of the wind box is connected to the plate 38 and an opening is provided to permit the plate 44 to extend out of the wind box for attachment to the buckstay beam 51. It can be seen that the outer surface of the wind box is provided with insulation 53 in a well known manner, although such insulation is omitted from many of the views of the drawings in order to facilitate understanding of the invention.

FIGS. 6, 7, and 8 show some of the details of the upper part of the wind box. For instance, in FIG. 6, which is a horizontal view of the upper connection of the wind box to the front wall of the furnace, a plate 54 is welded directly to the outer surfaces of the tubes 13 and from this plate extends the top wall 36 of the burner box. Extending also from the plate and overlying the wall 36 is a plate 55 having a few slots 56 extending into its outer edge. Supported on the upper surface of the shelf-like plate 55 is the corrugated lagging 57 forming the, outer layer of the normal furnace wall.

As is evident in FIG. 8, the top wall 36 of the furnace is provided with an inner section 58 which has longitudinal corrugations and with an outer section 59 having larger transverse corrugations. Located centrally of the section 58 is a cap 61 to which is attached the support 37 (not shown). In FIG. 8 is shown a buckstay beam 62 from which extends a plate 63 and an inner horizontal beam 26 from which extend spaced parallel plates 64 and 65. A pin 66 of square cross-section is locked in the plate 63 and extends through transversely elongated slots in the plates 64 and 65.

FIG. 7 shows a housing 67 extending upwardly from the top wall 36 of the wind box and provided at its upper end with a vertical sleeve 68. In the sleeve extends a rod 69 which extends upwardly for attachment to the main framework of the boiler. Its lower end is threadedly attached to a clevis 71 which, in turn, is pivotally attached by means of a pivot pin 72 to a vertical plate 73 which is attached to a horizontal connection beam 31 extending under the top wall 36.

The framework 24 is attached to the horizontal buckstay beam 62 extending along the front wall 15 of the furnace by an arrangement similar to the connecting means 43 shown in FIGS. 3 and 5 and the connecting means shown in FIG. 8. Extending from the particular buckstay 62 is a central plate above and below which reside plates extending rearwardly from the inner horizontal beams 26. A pin passes between these last-named two plates and resides in a slot in the plate attached to the buckstay. Now, referring to FIG. 9, an arrangement of burners 16 is very clearly shown whereby, as is evident, there are 25 connecting means each one provided with a slot and a pin. The transverse extent of each slot is determined by its position in the grid. Those connections labeled B, which is the central vertical row of connections, has no transverse extent, so that the pin locks the plates together firmly and does not permit relative transverse motion between them. In the central row, at the connections labeled A, the spacing between the upper and lower plates, i.e., the spacing which permits relative vertical motion between the plate coming from the boiler and the plate coming from the inner horizontal beams 26 is zero, so that vertical motion cannot take place between them. As is evident in the chart shown in FIG. 9, as one moves to the right and to the left from the center row, the transverse elongation of the slot becomes larger, thus permitting greater relative motion between the plates. Similarly, moving up or down from the central row labeled A, the space between the plates becomes larger and larger permitting greater vertical movement between the frame and the wall of the furnace.

It can be seen, then, that the present construction permits the expansion and contraction of the wind box relative to the furnace without any possibility of overstressing any of the support parts and causing a failure of the furnace or burner box. This is important because, without the use of the present invention, over a long period of time, cracks may develop; if such breaking of the envelope is allowed, the air and gas in the burner box can escape into the atmosphere. If the boiler is located in a building, the escape of gas (when the apparatus is used with a gas turbine) will poison the air and, furthermore,

there is a tremendous heat loss when turbine gas is allowed to escape. The escape of air means that, for a given load on the boiler, the fans must do more work and so must not only be of larger initial design, but will use more electricity or power. By the present construction in which the supporting frame for the burner box is allowed to expand and contract relative to the furnace wall and provision is made for stretching of the skin metal forming the outside of the burner box, all of these problems have been suitably taken care of in a novel manner.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit. thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

The invention having been thus described, what is claimed as new and desired to secure by Letters Patent is:

1. A furnace, comprising (a) a vertical wall including water tubes in spaced,

parallel relationship,

(b) a burner box front wall in spaced, parallel relationship to the said wall,

(c) a burner box top wall and burner box side walls extending between the vertical wall and the front wall, the top wall and the side walls are provided with corrugations extending at right angles to the 7 said vertical wall, the top wall and the side walls being also provided with corrugations which extend parallel to the said vertical wall, the first-recited corrugations being located immediately adjacent the said vertical wall, while the second-recited corrugations are located immediately adjacent the said front wall.

2. A furnace as recited in claim 1, wherein a forced air duct and a hot gas duct enter the bottom portion of the burner box.

3. A furnace as recited in claim 2, wherein the'side walls adjacent the bottom portion are provided with vertical corrugations only.

4. A furnace as recited in claim 1, including a framework, means supporting the said burner box front, top, and side walls on said framework, connection means joining said framework to said vertical wall to permit lateral sliding between the framework and the vertical wall.

A n e as e ted in claim 4, wherein the center of the framework is fixed to the Vertical wall and the lateral sliding takes place outwardly of the center.

6. A furnace as recited in claim 4, wherein the connection means are arranged in a rectangular grid pattern, and wherein those connections located on a horizontal line through the center of the grid pattern permits no vertical movement, while the connections above and below the line permit vertical movement in amounts that are greater in proportion to the vertical distance from the line, and wherein those connections located on a vertical line through the center of the grid pattern permit no horizontal movement, while the connections sideways of the said vertical line permit horizontal movement in amounts that are greater in proportion to the horizontal distance from the line.

7. A furnace as recited in claim 6, wherein each connection between the vertical wall and the framework consists of two vertically-spaced horizontal first tongues joined by a vertical pin and of a horizontal second tongue- References Cited UNITED STATES PATENTS 2,125,019 7/1938 Haynes 1581.5 X 2,882,871 4/1959 Koch 122-478 FOREIGN PATENTS 936,539 9/1963 Great Britain.

KENNETH W. SPRAGUE, Primary Examiner. 

